Welding apparatus



Nov., 7, X939. mA 1 ECKMAN WELDING APPARATUS Filed July 5, 19158INVENTOR. MER/L, L. EcKMH/Y Z/g, )LZ2/1e ATTORNEYS Patented Nov. 7, 1939UNITED STATES WELDING APPARATUS Merl L. Eckman, Cleveland, Ohio,assignor to The American Coach & Body Company, Cleveland, Ohio, acorporation of Ohio Application July 5, 1938, Serial No. 217,375

6 Claims.

This invention relates to welding apparatus and particularly to thattype which includes long ilexible conductors with electrodes positionedat the ends thereof so that they may be transported to the work.

One of the diiiiculties experienced in using a portable electrode isthefact that the operator may not know precisely when he is exertingadequate pressure of the electrode against the work to make asatisfactory weld. This pressure must vary with the gauge of the metalto be welded and hence considerable skill is required to producesatisfactory results. I

An object of the present invention is to provide a device whichautomatically requires the application of a predetermined pressurebetween the electrode and work before current can flow therethrough.Additionally, the invention includes a device which may be calibratedfor metals of different thickness so that the operator may be table tocontrol the pressure exerted to suit any gauge of metal to be welded.

Referring now to the drawing, Fig. 1 illustrates a welding deviceembodying my invention; Fig. 2 o is a longitudinal section taken throughthe welding gun; Fig. 3 is a top plan View of the gun shown in Figs. 1and 2; Figs. 4 and 5 are sections taken on the correspondingly numberedlines in Fig. 3, and Fig. 6 is a wiring diagram.

30 A welding apparatus with which my invention is illustrated comprisesa transformer I which is suitably mounted on an overhead trackway II andwhich is provided with flexible conductors I2 and I3, to the ends ofwhich are connected 35 electrodes I4 and I5 respectively. In thisillustration, the plates to be welded together are indicated at and 2|respectively. In practice, the

electrode I4 is either clamped or held `by an operator against the plate20 while the electrode I5 40 is pressed by another operator against theplate 2 I To control the pressure between the electrode I5 and the plate2|, I have shown the electrode as being attached to a carrier or gunwhich is provided with a handle 26 that may be attached 45 The handlecomprises a relatively stationary portion that is fastened, asheretofore stated, to the electrode carrier, and a movable portion 30which is pivoted to the stationary portion 3l. The

movable portion comprises a hand grip against which pressure is exerted,both for pressing the electrode against the work, and for causing awelding current to flow therethrough.

In the preferred arrangement, the stationary 55 part of the handle '1sbifurcated to receive a.

thereto by suitable fastening members 21 and 28.

tongue 32 which forms an extension of the grip portion 30 and the tongueis adapted to engage a shoulder 33 on the stationary part so as to limitoutward movement of the grip portion with respect to the stationaryportion. The upper ends 5 of the stationary and movable portions areprovided with registering apertures 35 and 36 respectively. A selfcontained push button switch 31 is positioned Within the aperture 35`and is provided with a stop in the form of a ilange 38 which abutsagainst a wall 39 on the stationary part of the handle. The stationarypart, as shown in Figs. 3 and 4, has arms 40 extending toward the gripportion and providing' a guideway for arm 4I which forms part of thegrip andwhich extends toward the stationary portion. A spring isdisposed within the passageway 3 6 and bears at one end against the ange38 and at the other end against a washer 46 which in turn seats againstan adjusting nut 41 by means of which 20 tension of the spring may bevaried. The purpose of adjusting the tension on the spring is to varythe pressure which must be exerted upon the grip portion in order toactuate the push button controller 3l. The extent of the spring movement25 can be observed through an opening 50 in the top of the grip portionthrough which a tongue 5I on the washer 46 extends. Suitable markings 52adjacent the openings may be calibrated to indicate the gauge of metalthat is to be welded.

To actuate the controller by movement of the hand grip, I have shown athreaded spindle which extends through a correspondingly threadedpassageway in the adjusting nut 41 and which is adapted to bear againstthe push button 35 plunger 56. The spindle may be adjustably positioned-within the nut 4l in 'order to compensate for any variation in size ofthe push button mechanism. Current may be conducted to the push buttonthrough a conductor which may extend 40 along the cable I3 and beconnected to a relay which is illustrated in Fig. 1 as being attached tothe transformer casing.

Normally the spring 45 urges the two parts of the handle away from eachother, but such movement is limited by contact between the tongue 32 andthe shoulder 33. When the gun is to be used, however, the adjustingscrew 41 is manipulated until the tongue 5I corresponds to the markings52 which represent the gauge of the metal to be welded. Thereupon, theoperator places the electrode against the work and pushes against thehand grip. Pressure is exerted until the tension of the spring 45 isovercome and the push button plunger 55 is depressed to close thecircuit 5 5.

through the control mechanism that initiates the ilow of current throughthe electrode. It is to be understood that the apparatus is to beprovided with suitable timing equipment which automati- 5 cally limitsthe time during which the current is allowed to ilow, this intervalbeing, of course, predetermined and iixed in accordance with thecharacteristics of the apparatus and current utilized. It is sumcient tostate that the operator need only press the electrode against the workand that the ilow of current starts automatically and in the correctamount toproduce a satisfactory weld.

In Fig. 6, I have shown a wiring diagram wherein the primary of thetransformer is indicated at P and the secondary at S. Conductors I2 andI3 from the secondary lead to the electrodes I4 and l5 while the controlmechanism for causing the iiow of current is connected to the primarycircuit. In the form illustrated, the control comprises a relay 10 whichis governed by the push button mechanism.

From the foregoing description, it is apparent that my inventionprovides a mechanism that.

'is contained within the electrode handle for automatically obtainingvthe required degree of pressure for any given thickness of metal to beWelded, and that the pressure setting may be adjusted readily to suitany particular gauge desired. A further advantage of my invention is thefact that the arrangement enables an operator to exert pressure by adirect push against the handle thereby enabling him to accomplish thedesired result without undue fatigue.

I claim:

1. In a. welding apparatus, the combination of an electrode carrierhaving a handle comprising relatively stationary and relatively movablemembers, said members being pivotally connected andhaving registeringopenings, a push button controller in one of the openings and means inthe other opening for engaging and actuating the controller, said meansincluding a spring and an positions by means of which the extent of thepressure required for actuating the switch may be varied to suit theconditions under which the electrode is to be used.

3. In combination, an electrode carrier having a handle, said handlecomprising a relatively stationary and a relatively movable member, apush button switch carried by one of the members, and means foractuating the switch carried by the other member, said means including aspring, an adjusting nut for constraining the spring at increasingvalues of pressure, and a member extending through the adjusting screwand ln threaded engagement therewith and adapted to bear against theswitch, for actuating the same upon movement of one of the members withreference to the other.

4. A handle for an electrode carrier comprising two relatively movablemembersl having registering openings extending therethrough, a pushbutton controller in one of the openings and an actuator for saidcontroller in the other opening, said actuator including a spring, meansto apply a xed load on the spring and an indicator that is actuatedthereby for indicating the load on the spring.

5. An electrode carrier having a handle therefor, the handle including agrip portion that is pivoted for movement with respect to the carrier,said grip portion having an opening extending therethrough, a spring andan adjusting nut located within the opening to constrain the spring atincreasing valuesof pressure, the wall of the opening having a slottherein, a washer interposed between the spring and adjusting nut, andhaving a tongue extending through the slot, and a scale on the gripportion adjacent the slot, a threaded spindle extending through theadjusting nut and adjustable independently of the nut and a circuitcontroller adapted to be engaged by the spindle upon movement of thegrip portion with reference to the carrier.

6. A welding apparatus comprising an electrode carrier in the form of abarrel having an electrode at one end thereof, a handle in the form of ahand grip pivotally connected to the other end of the carrier andextending transversely of the axis thereof, whereby said hand grip mayfurnish means for directly shoving on the carrier in a direction of itslength and without external anchorage to hold the electrode against thework, an electric switch actuated by the movement of the handle towardthe carrier, and a spring resisting such movement.

MERIL L. ECKMAN.

